November 26, 2012

Evidence Shows Vitamin D Helps Slow Cancer Cells

McGill University researchers have discovered vitamin D helps to slow the progression of cells of cancer from premalignant to malignant states.

The researchers reported in the journal Proceedings of the National Academy of Sciences vitamin D helps to inhibit both the production and function of the protein cMYC, which drives cell division and is active at elevated levels in more than half of all cancers.

Vitamin D has been known to have a wide range of physiological effects. Scientists have understood that a correlation exists between insufficient amounts of vitamin D and increased incidence of a number of cancers.

The correlations between the vitamin and cancers are strong for those cancers of the digestive tract, including colon cancer and certain forms of leukemia.

“For years, my lab has been dedicated to studying the molecular mechanisms of vitamin D in human cancer cells, particularly its role in stopping their proliferation,” Professor John White of the Faculty of Medicine's Department of Physiology, said in a statement.

Vitamin D can be obtained from limited dietary sources as well as from direct exposure to the sun during the spring and summer months. Having a lack of exposure to the sun, mixed with a combination of poor dietary intake, has created vitamin D deficiency or insufficiency in large populations around the world.

White said the team discovered vitamin D controls both the rate of production and the degradation of cMYC. They also found it strongly stimulates the production of a natural antagonist of cMYC known as MXD1, which shuts down cMYC function.

For the study, the researchers applied vitamin D to the skin of mice and observed a drop in the level of cMYC, discovering evidence of a decrease in its function. They also found strongly elevated levels of cMYC in a number of tissues, including skin and the lining of the colon.

“Taken together, our results show that vitamin D puts the brakes on cMYC function, suggesting that it may slow the progression of cells from premalignant to malignant states and keep their proliferation in check," White said in the statement.

He said the team hopes the study will encourage people to maintain adequate vitamin D levels. Also, he said they hope the results will stimulate the development of large trials to test the effects of adequate supplementation.